Re: [NTLK] Need a new backlight

From: Calvin Grier (cgrier_at_ix.netcom.com)
Date: Thu Feb 05 2004 - 07:07:24 PST


I was going to try and stay out of this "discussion" because I did not want
to throw fuel on the fire. However, I've just got to make some comments.

1) The technology of EL backlights has improved since Apple made theirs.
Phosophor efficiencies and encapsulation techniques have improved as prices
have come down. This has not in any way changed the basic electical
construction of EL backlights, since they act more-or less like a capacitor
in an electronic circuit. The electrical characteristics depend directly on
the area of the EL lamp, and spacing between layers, and the dialectric
between them. That hasn't changed very much since 1996.

2) Brighter is not always better. Imagine using your Newton in a dark room
and turning on a very bright backlight. Looking straight on at a lamp as
bright as a headlight is not going to be good for your night-vision. IF PBK
has found a way to "dim" the EL backlight on a Newton so you can use it in a
dark room, then maybe they don't have to worry about this issue.

3) If the new backlight is so great, why don't they show it? There's not one
picture showing the backlight on their web page or in the installation
manual. How about a side-by-side with an origianl Apple backlight? If you go
to my web page, I show engineering drawings of our white EL backlight, and
several pictures of the actual end-product we're selling for $29 US.
www.adago.net (Side-note: our backlight was made to tighter tollerances than
Apple's, and fits like a glove into the LCD module.) Here are a few links to
EL pictures:
www.adago.net/images/backlightcloseup.jpg
www.adago.net/images/backlight1_big.jpg

4) There's one reason Apple decided on green when they made the Newton:
GREEN phosphors are by-far the most efficient phosphors that can be used in
an EL panel. (Just doing a little research on the web will tell you that.)
The LCD is more-or-less color agnostic. I don't have data to back this up
but it would be very easy to come up with some simple tests - using
non-functional LCDs - to show if the LDC was preferentially transmitting
red, green or blue. I might do that and post the results on the web.

5) I'll admit to never having attempted to reverse engineer the EL backlight
circuit in the Newton. However, the white backlight I'm selling gives off
70% of the light of the original Apple backlight and uses the same amount of
battery power. Our White EL backlight was designed to replicate the
electrical properties of the Apple original so no other modifications are
necessary. White is also more eye-pleasing - how many green paper notebooks
have you ever purchased?

6) I'd really like to know what the intrinsic brightness of the PBK
backlight is - when driven by a modified and unmodified Newton inverter. I
wonder if they'd post that? :-)

BTW, I still have some of the white backlights available for purchase at $29
US. They aren't quite as bright as the original, but they have more
"eye-appeal" and are a lot less expensive than other alternatives.

--Calvin Grier
www.adago.net

-- 
This is the NewtonTalk list - http://www.newtontalk.net/ for all inquiries
List FAQ/Etiquette/Terms: http://www.newtontalk.net/faq.html
Official Newton FAQ: http://www.chuma.org/newton/faq/


This archive was generated by hypermail 2.1.5 : Fri Feb 06 2004 - 01:00:00 PST